The use of metformin in type 1 diabetes: a systematic review of efficacy

Insulin Resistance in Type 1 Diabetes: Pathophysiological, Clinical, and Therapeutic Relevance

People with type 1 diabetes (T1D) are usually considered to exclusively exhibit β-cell failure, but they frequently also feature insulin resistance. This review discusses the mechanisms, clinical features, and therapeutic relevance of insulin resistance by focusing mainly on human studies using gold-standard techniques (euglycemic-hyperinsulinemic clamp). In T1D, tissue-specific insulin resistance can develop early and sustain throughout disease progression. The underlying pathophysiology is complex, involving both metabolic- and autoimmune-related factors operating synergistically. Insulin treatment may play an important pathogenic role in predisposing individuals with T1D to insulin resistance. However, the established lifestyle-related risk factors and peripheral insulin administration inducing glucolipotoxicity, hyperinsulinemia, hyperglucagonemia, inflammation, mitochondrial abnormalities, and oxidative stress cannot always fully explain insulin resistance in T1D, suggesting a phenotype distinct from type 2 diabetes. The mutual interaction between insulin resistance and impaired endothelial function further contributes to diabetes-related complications. Insulin resistance should therefore be considered a treatment target in T1D. Aside from lifestyle modifications, continuous subcutaneous insulin infusion can ameliorate insulin resistance and hyperinsulinemia, thereby improving glucose toxicity compared with multiple injection insulin treatment. Among other concepts, metformin, pioglitazone, incretin-based drugs such as GLP-1 receptor agonists, sodium-glucose cotransporter inhibitors, and pramlintide can improve insulin resistance, either directly or indirectly. However, considering the current issues of high cost, side effects, limited efficacy, and their off-label status, these agents in people with T1D are not widely used in routine clinical care at present.

Exploring the clinical connections between epilepsy and diabetes mellitus: Promising therapeutic strategies utilizing agmatine and metformin

PURPOSE

Diabetes mellitus (DM) and epilepsy and the psychological and socio-economic implications that are associated with their treatments can be quite perplexing. Metformin is an antihyperglycemic medication that is used to treat type 2 DM. In addition, metformin elicits protective actions against multiple diseases, including neurodegeneration and epilepsy. Recent studies indicate that metformin alters the resident gut microbiota in favor of species producing agmatine, an arginine metabolite which, in addition to beneficially altering metabolic pathways, is a potent neuroprotectant and neuromodulant.

METHODS

We first examine the literature for epidemiological and clinical evidences linking DM and epilepsy. Next, basing our analyses on published literature, we propose the possible complementarity of agmatine and metformin in the treatment of DM and epilepsy.

RESULTS

Our analyses of the clinical data suggest a significant association between pathogeneses of epilepsy and DM. Further, both agmatine and metformin appear to be multimodal therapeutic agents and have robust antiepileptogenic and antidiabetic properties. Data from animal and clinical studies largely support the use of metformin/agmatine as a double-edged pharmacotherapeutic agent against DM and epilepsy, particularly in their concurrent pathological occurrences.

CONCLUSION

The present review explores the evidences and available data on possible uses of metformin/agmatine as pertinent antidiabetic and antiepileptic agents. Our hope is that this will stimulate further research on the therapeutic actions of these multimodal agents, particularly for subject-specific clinical outcomes.

Glucose Disorders

Glucose disorders are the most common endocrine condition in the primary care setting. The conditions overlap and are better viewed as a spectrum rather than discrete entities. Multiple treatment agents are now available for diabetes mellitus which include long-acting and short-acting insulins and medications targeting the various pathways of diabetes including liver gluconeogenesis, increasing peripheral insulin sensitivity, stimulating pancreatic insulin production, eliminating glucose renally, decreasing carbohydrate gastrointestinal absorption, and targeting the body's incretin system. Various endocrine conditions can cause secondary hyperglycemia or hypoglycemia. Medications and physiologic stress can affect glucose levels. Genetic syndromes causing enzyme deficiencies underlie a small portion of glucose disorders.

Metformin beyond type 2 diabetes: Emerging and potential new indications

Metformin is best known as a foundational therapy for type 2 diabetes but is also used in other contexts in clinical medicine with a number of emerging and potential indications. Many of its beneficial effects may be mediated by modest effects on weight loss and insulin sensitivity, but it has multiple other known mechanisms of action. Current clinical uses beyond type 2 diabetes include: polycystic ovarian syndrome; diabetes in pregnancy/gestational diabetes; prevention of type 2 diabetes in prediabetes; and adjunct therapy in type 1 diabetes. As metformin has been in clinical use for almost 70 years, much of the underpinning evidence for its use in these conditions is, by definition, based on trials conducted before the advent of contemporary evidence-based medicine. As a result, some of the above-established uses are 'off-label' in many regulatory territories and their use varies accordingly in different countries. Going forward, several current 'repurposing' investigational uses of metformin are also being investigated: prevention of cancer (including in Li Fraumeni syndrome), renal protection, Alzheimer's disease, metabolic dysfunction-associated steatotic liver disease and promotion of healthy ageing. Despite the longevity of metformin and its important current roles beyond type 2 diabetes in clinical medicine, it has further potential and much research is ongoing.

Beneficial In Vitro Effects of Polysaccharide and Non-Polysaccharide Components of Dendrobium huoshanense on Gut Microbiota of Rats with Type 1 Diabetes as Opposed to Metformin

The extract of Dendrobium huoshanense, a traditional Chinese medicinal and food homologous plant belonging to the family Orchidaceae, was previously reported to have hypoglycemic and antioxidant effects. In this study, the direct effects of polysaccharide (DHP) and non-polysaccharide (NDHP) components of D. huoshanense, as well as its water extract (DHWE) were compared with that of metformin (an antidiabetic drug) on the gut microbiota (collected from fecal flora) of rats with streptozotocin-induced type 1 diabetes (T1D) using an in vitro fermentation method. The results showed that DHWE, DHP, and NDHP reduced pH and increased bacterial proliferation and short-chain fatty acid (SCFA) content in fermentation broth. DHWE, DHP, NDHP and metformin promoted the production of acetic and propionic acid, acetic acid, propionic acid and butyric acid, and propionic acid, respectively. DHWE, DHP, and NDHP reduced the abundance of Proteobacteria (subdominant pathogenic bacteria) and increased the abundance of Firmicutes (dominant beneficial gut bacteria). NDHP also reduced the abundance of Bacteroidetes (beneficial and conditional pathogenic). Metformin increased the abundance of Proteobacteria and reduced the abundance of Firmicutes and Bacteroidetes. At the genus level, NDHP promoted the proliferation of Megamonas and Megasphaera and decreased harmful bacteria (e.g., Klebsiella), and DHP increased the abundance of Prevotellaceae (opportunistic and usually harmless). By contrast, metformin increased the abundance of harmful bacteria (e.g., Citrobacter) and reduced the abundance of beneficial bacteria (e.g., Oscillospira). Our study indicates that DHWE, DHP, and NDHP are potentially more beneficial than metformin on the gut microbiota of T1D rats in vitro.

Metformin: Past, Present, and Future

PURPOSE OF REVIEW

This review provides the most recent update of metformin, a biguanide oral antihyperglycemic drug used as a first-line treatment in type 2 diabetes mellitus.

RECENT FINDINGS

Metformin continues to dominate in the world of antidiabetics, and its use will continue to rise because of its high efficiency and easy availability. Apart from type 2 diabetes, research is exploring its potential in other conditions such as cancer, memory loss, bone disorders, immunological diseases, and aging. Metformin is the most prescribed oral antidiabetic worldwide. It has been in practical use for the last six decades and continues to be the preferred drug for newly diagnosed type 2 diabetes mellitus. It reduces glucose levels by decreasing hepatic glucose production, reducing intestinal glucose absorption, and increasing insulin sensitivity. It can be used as monotherapy or combined with other antidiabetics like sulfonylureas, DPP-4 inhibitors, SGLT-2 inhibitors, or insulin, improving its efficacy. Metformin can be used once or twice daily, depending on requirements. Prolonged usage of metformin may lead to abdominal discomfort, deficiency of Vitamin B12, or lactic acidosis. It should be used carefully in patients with renal impairment. Recent studies have explored additional benefits of metformin in polycystic ovarian disease, gestational diabetes mellitus, cognitive disorders, and immunological diseases. However, more extensive studies are needed to confirm these additional benefits.

Targeting TAM-secreted S100A9 effectively enhances the tumor-suppressive effect of metformin in treating lung adenocarcinoma

Metformin's effect on tumor treatment was complex, because it significantly reduced cancer cell proliferation in vitro, but made no difference in prognosis in several clinical cohorts. Our transcriptome sequencing results revealed that tumor-associated macrophage (TAM) infiltration significantly increased in active lung adenocarcinoma (LUAD) patients with long-term metformin use. We further identified that the tumor suppressive effect of metformin was more significant in mice after the depletion of macrophages, suggesting that TAMs might play an important role in metformin's effects in LUAD. Combining 10X Genomics single-cell sequencing of tumor samples, transcriptome sequencing of metformin-treated TAMs, and the ChIP-Seq data of the Encode database, we identified and validated that metformin significantly increased the expression and secretion of S100A9 of TAMs through AMPK-CEBP/β pathway. For the downstream, S100A9 binds to RAGE receptors on the surface of LUAD cells, and then activates the NF-κB pathway to promote EMT and progression of LUAD, counteracting the inhibitory effect of metformin on LUAD cells. In cell-derived xenograft models (CDX) and patient-derived xenograft models (PDX) models, our results showed that neutralizing antibodies targeting TAM-secreted S100A9 effectively enhanced the tumor suppressive effect of metformin in treating LUAD. Our results will enable us to better comprehend the complex role of metformin in LUAD, and advance its clinical application in cancer treatment.

Prescribing patterns of adjunctive therapy for the treatment of type 1 diabetes mellitus among Australian endocrinologists

BACKGROUND

Many people living with type 1 diabetes (type 1 diabetes mellitus (T1DM)) do not meet glycaemic targets. Adjunctive therapies have both risks and metabolic benefits and may have a role in selected patients.

AIM

To review the prescribing patterns of adjunctive therapy for the treatment of T1DM diabetes in Australia.

METHODS

We conducted an online survey of Australian endocrinologists and endocrinology registrars. We surveyed the frequency of, motivations and concerns regarding the prescription of metformin, dipeptidyl peptidase-4 (DPP-IV) inhibitors, sodium-glucose transport protein 2 (SGLT-2) inhibitors and glucagon-like peptide 1 receptor agonist (GLP1RA) in T1DM.

RESULTS

Fifty-two practitioners participated. Most respondents (94%) had prescribed adjuncts for the treatment of T1DM in some form. Weight (89%), large insulin doses (73%), glycaemic variability (52%), high HbA1c (48%) and the presence of cardiovascular disease (48%) were the most common factors determining the use of adjuncts. The most commonly prescribed adjuncts were metformin (94%) and SGLT-2 inhibitors (65%). Respondents who had never prescribed an SGLT-2 inhibitor (n = 18) reported risk of diabetic ketoacidosis (DKA) (100%), off-label status (39%), lack of evidence (39%), withdrawal of support from the European Medicines Agency (17%) and cost (17%) as factors contributing to their decision. Thirty-one respondents (60%) had prescribed a GLP1RA. Among those who had never prescribed a GLP1RA (n = 21), off-label status (57%), lack of evidence (48%), cost (38%) and expected lack of efficacy (14%) were factors affecting their decision. Only five respondents (10%) had prescribed a DPP-IV inhibitor.

CONCLUSION

Australian endocrinologists commonly prescribe adjuncts to address cardiometabolic concerns in T1DM. DKA risk and off-label status are significant factors contributing to reluctance to prescribe.

Insulin Resistance in Adolescents and Youth With Type 1 Diabetes: A Review of Problems and Solutions

Though insulin resistance (IR) was previously considered a feature of only type 2 Diabetes (T2DM), its development in type 1 Diabetes (T1DM) is not an uncommon occurrence, the causes of which are multifactorial (gender, pubertal status, diabetes duration, ethnicity, genetics, adiposity, glycemic control, chronic inflammation). Despite improvements in glucose, blood pressure and lipid profile, vascular complications (coronary artery disease and nephropathy) continue to remain common causes of morbidity and mortality in T1DM. Aggressive glycemic control reduces but does not eliminate the risk of IR. IR accelerates the development of micro and macrovascular complications, many of which can be potentially reversed if diagnosed and managed early. Lack of endogenous insulin production makes estimation of insulin sensitivity in T1DM difficult. As hyperinsulinemic-euglycemic clamp studies are cumbersome and invasive, the use of prediction equations for calculating estimated insulin sensitivity may prove to be useful. Along with intensive insulin therapy, dietary modifications and increasing physical activity, the role of Metformin in managing IR in T1DM is becoming increasingly popular. Metformin adjunct therapy in T1DM has been shown to improve insulin sensitivity, glycemic control, lipid profile, body composition, vascular smooth muscle function, thereby reducing the risk of vascular complications, as well as reversal of early vascular dysfunction. However, further studies to assess long-term efficacy and safety of Metformin use in adolescents and youth with T1DM are needed. This review aims at revisiting the pathophysiology of IR in T1DM and techniques of identifying those at risk so as to put into action various strategies for management of the same.

The Effectiveness of Metformin in Diabetes Prevention: A Systematic Review and Meta-Analysis

Diabetes mellitus is a growing global health concern, and prevention strategies play a crucial role in reducing its burden. Metformin has been widely studied as a potential intervention for diabetes prevention, but its overall effectiveness and impact on various populations remain unclear. This study aims to provide a comprehensive synthesis of the available evidence on the effectiveness of metformin in diabetes prevention. A systematic search was conducted in PubMed, Scopus, ScienceDirect, and Google Scholar for articles published from inception to June 2023. The reference lists of the included studies were also searched to retrieve possible additional studies. Any quantitative data were analyzed using Review Manager 5.4. A P-value of 0.05 was adopted as the significance threshold. Our analysis included 17 studies with a total sample size of 30,474. Our meta-analysis included two key analyses. First, the meta-analysis evaluating the effects of metformin on prediabetes demonstrated a significant reduction in the risk of progressing to type 2 diabetes mellitus (T2DM). The pooled odds ratio (OR) was 0.65 (95% confidence interval [CI] 0.53-0.80), indicating a 35% lower odds of developing T2DM among individuals with prediabetes who received metformin interventions compared to control groups. Secondly, the meta-analysis assessing the efficacy of metformin interventions in preventing T2DM yielded a significant reduction in the risk of developing the disease. The pooled risk ratio was 0.58 (95% CI 0.44-0.77), indicating a 42% lower risk of developing T2DM in individuals receiving metformin interventions compared to those in non-metformin intervention groups. These findings provide strong evidence for the effectiveness of metformin in preventing the progression of prediabetes to T2DM and reducing the overall incidence of the disease. The review demonstrated that metformin is effective in reducing the risk of developing diabetes mellitus among individuals at risk for the disease. The findings highlight the potential of metformin as a valuable intervention for diabetes prevention, particularly in high-risk populations.

Effects of metformin on glycaemic variability in combination with insulin in overweight/obese patients with type 1 diabetes

BACKGROUND

The prevalence of overweight and obesity in type 1 diabetes mellitus (T1DM) individuals is increasing. Overweight people with T1DM may be insulin resistant. Glycaemic variability (GV) is an emerging measure of glycaemic control. The aim of this study is to investigate whether metformin, in adjunct to insulin, would have any favourable effect on GV.

METHODS

This was a multi-centre, open-label randomised crossover study. Twenty-four overweight/obese T1DM patients aged ⩾18 years old with HbA1c ⩾ 7.0% (53 mmol/mol) were recruited and randomised into two study arms. For first 6-week, one arm remained on standard of care (SOC), the other arm received metformin, adjunctive to SOC. After 2-week washout, patients crossed over and continued for another 6 weeks. Glycaemic variability, other glycaemic parameters and metabolic profile were monitored.

RESULTS

There were significant reduction in metformin group for GV: mean (0.18 ± 1.73 vs -0.95 ± 1.24, p = 0.014), %CV (-15.84 (18.92) vs -19.08 (24.53), p = 0.044), glycemic risk assessment of diabetes equation (-0.69 (3.83) vs -1.61 (3.61), p = 0.047), continuous overlapping net glycaemic action (0.25 ± 1.62 vs -0.85 ± 1.22, p = 0.013), J-index (-0.75 (21.91) vs -7.11 (13.86), p = 0.034), time in range (1.13 ± 14.12% vs 10.83 ± 15.47%, p = 0.032); changes of systolic blood pressure (2.78 ± 11.19 mmHg vs -4.30 ± 9.81 mmHg, p = 0.027) and total daily dose (TDD) insulin (0.0 (3.33) units vs -2.17 (11.45) units, p = 0.012). Hypoglycaemic episodes were not significant in between groups.

CONCLUSION

Metformin showed favourable effect on GV in overweight/obese T1DM patients and reduction in systolic blood pressure, TDD insulin, fasting venous glucose and fructosamine.

A Pilot Study to Assess Effect of Metformin Therapy on Prevention of Double Diabetes in Indian Adolescents with Type-1 Diabetes

Introduction

Increased prevalence of metabolic syndrome in Indian adolescents owing to the obesity epidemic leads to double diabetes (DD), which is associated with an increased risk of complications in type-1 diabetes (T1D). Metformin may be a useful intervention for the prevention and treatment of insulin resistance in T1D. We conducted this pilot randomized controlled trial with the objective of investigating the effect of metformin on insulin sensitivity in Indian adolescents with T1D.

Method

This pilot randomized controlled trial was performed on 59 participants with T1D aged 10-19 years distributed uniformly by gender and puberty across two groups with a 3-month intervention period. The intervention group received metformin (weight less than 60 kg received 500 mg twice daily and more than 60 kg received 1 gm twice daily) and non-metformin group received standard of care for diabetes. Anthropometric, clinical details, biochemistry and insulin sensitivity indices (ISI) were evaluated using standard protocols at baseline and endline.

Result

22.2% of subjects from non-metformin group and 12.5% from metformin group were at the risk of the development of DD. The odds ratio and relative risk for the development of DD in non-metformin subjects were 2.0 and 1.4, respectively, as compared to participants in metformin group. The mean improvement in ISI ranged from 1.4% to 4.6% in participants on metformin as opposed to deterioration of -2% to -14.1% in non-metformin group. On performing the paired sample t-test, the reduction in ISI in non-metformin group was significant.

Conclusion

Metformin may prevent deterioration in insulin sensitivity in Indian adolescents with T1D.

A perspective on treating type 1 diabetes mellitus before insulin is needed

Type 1 diabetes mellitus (T1DM) is a progressive autoimmune disease that starts long before a clinical diagnosis is made. The American Diabetes Association recognizes three stages: stage 1 (normoglycaemic and positive for autoantibodies to β-cell antigens); stage 2 (asymptomatic with dysglycaemia); and stage 3, which is defined by glucose levels consistent with the definition of diabetes mellitus. This Perspective focuses on the management of the proportion of individuals with early stage 3 T1DM who do not immediately require insulin; a stage we propose should be termed stage 3a. To date, this period of non-insulin-dependent T1DM has been largely unrecognized. Importantly, it represents a window of opportunity for intervention, as remaining at this stage might delay the need for insulin by months or years. Extending the insulin-free period and/or avoiding unnecessary insulin therapy are important goals, as there is no risk of hypoglycaemia during this period and the adherence burden on patients of glycaemic monitoring and daily adjustments for diet and exercise is substantially reduced. Recognizing the pressing need for guidance on adequate management of children and adults with stage 3a T1DM, we present our perspective on the subject, which needs to be tested in formal and adequately powered clinical trials.

Neuromodulatory effect of the combination of metformin and vitamin D3 triggered by purinergic signaling in type 1 diabetes induced-rats

Several studies have indicated the vitamin D deficiency in the development of macro- and microvascular complications of diabetes mellitus (DM) including DM-related cognitive dysfunction. The purinergic system plays an important role in the modulation of a variety of mechanisms, including neuroinflammation, plasticity, and cell-cell communication. In addition, purines, their receptors, and enzymes can regulate the purinergic axis at different levels in type 1 DM (T1DM). This study evaluated the effects of vitamin D₃ alone or in combination with metformin in the behavioral performance of streptozotocin-induced T1DM rats. The effects of this combination on the metabolism of ATP and ADP were also studied by NTPDase (CD39), AMP by 5'-nucleotidase (CD73), and adenosine by adenosine deaminase (E-ADA) in the brain and peripheral lymphocytes of type 1 diabetic STZ-induced rats. The results showed that anxiety and memory loss from the DM condition reverted after 30 days of vitamin D₃ treatment. Furthermore, the DM state affected systemic enzymes, with no effect on the central enzymes hydrolyzing extracellular nucleotides and nucleosides. Vitamin D₃ treatment positively regulated ectonucleotidase (NTPDase and 5'-nucleotidase) activity, E-ADA, and the purinergic receptors as a mechanism to prevent oxidative damage in the cerebral cortex of T1DM rats. A neuroprotector effect of vitamin D₃ through adenosine signaling was also observed, by regulating A1 and A_2A receptors proteins levels. The present findings suggest that purinergic signaling through vitamin D₃ modulation may be a novel alternative strategy for T1DM treatment, and may compensate for the negative changes in the central nervous system.

The METRO study: a retrospective analysis of the efficacy of metformin for type 2 diabetes in Japan

Metformin monotherapy as first-line treatment for patients with type 2 diabetes (T2D) has been shown to effectively improve blood glucose levels and motivation to undergo treatment and prevent complications. However, no studies have reported its effect when combined with other drugs or compared the effect based on administration time. This study aimed to investigate the effect of metformin administration in Japanese patients with T2D, examine how the introduction line impacts the effect of metformin, and examine the characteristics of patients demonstrating improved blood glucose levels. Data on characteristics of patients who were newly prescribed metformin with no shifting of hypoglycemic agents in the subsequent 24-week observation period, and their age [mean, 56.8 years], body mass index [mean, 27.5 kg/m²], glycated hemoglobin [HbA1c] [mean, 8.1%], and duration of diabetes [mean, 3.0 years] were obtained from the medical records of 201 patients. The changes in HbA1c by introduction line after 24 weeks were -1.59%, -0.91%, -0.89%, and -0.65% in the first, second, third, and fourth induction lines, respectively; earlier introduction more significantly improved blood glucose. The factors significantly associated with HbA1c changes were early introduction, high baseline HbA1c, high estimated glomerular filtration rate, decreased insulin secretion, short estimated duration of diabetes, and increased metformin dose. Furthermore, factors contributing to the largest HbA1c improvement by metformin were high baseline HbA1c and early administration. Metformin is expected to lower blood glucose levels in Japanese patients with T2D, even in those with decreased insulin secretion, due to its early introduction as a first-line drug.

A combination of metformin and insulin improve cardiovascular and cerebrovascular risk factors in individuals with type 1 diabetes mellitus

BACKGROUND

This study aims to further clarify whether the addition of metformin to insulin treatment improve cardiovascular and cerebrovascular risk factors in individuals with T1DM.

METHODS

Electronic databases were searched for randomized controlled trials in which the efficacy and safety of metformin were compared with those of a placebo for risk factors of cardiovascular and cerebrovascular disease among individuals with T1DM, and a meta-analysis was conducted.

RESULTS

Thirteen cardiovascular studies were identified. In the metformin group, mean carotid intimal media thickness was significantly reduced by 0.03 mm, ascending aortic pulse wave velocity by 6.3 m/s, descending aortic wall shear stress by 1.77 dyn/cm² (P = 0.02), insulin daily dose by 0.05 U/kg/d, body weight by 2.27 kg, fat-free mass by 1.32 kg, body mass index by 0.58 kg/m², hip circumference by 0.29 m, and low-density lipoprotein by 0.16 mmol/L, all above are P < 0.05. In the metformin group, flow-mediated dilation was increased by 1.29 %, glucose infusion rate/insulin by 18.22 mg/(kg⋅min)/μIU/μL, and waist-to-hip ratio by 0.02, all above are P < 0.00001. The metformin group showed no differences in blood pressure, reactive hyperemia index, waist circumference, triglyceride, total cholesterol, high-density lipoprotein cholesterol, or body mass index Z score. For cerebrovascular studies were identified. But none of them had a risk factor assessment.

CONCLUSIONS

Metformin can ameliorate cardiovascular and cerebrovascular risk factors through non-hypoglycemic multiple pathways in individuals with T1DM.

Highlighting the Role of Obesity and Insulin Resistance in Type 1 Diabetes and Its Associated Cardiometabolic Complications

PURPOSE OF REVIEW

This narrative review appraises research data on the potentially harmful effect of obesity and insulin resistance (IR) co-existence with type 1 diabetes mellitus (T1DM)-related cardiovascular (CVD) complications and evaluates possible therapeutic options.

RECENT FINDINGS

Obesity and IR have increasingly been emerging in patients with T1DM. Genetic, epigenetic factors, and subcutaneous insulin administration are implicated in the pathogenesis of this coexistence. Accumulating evidence implies that the concomitant presence of obesity and IR is an independent predictor of worse CVD outcomes. The prevalence of obesity and IR has increased in patients with T1DM. This increase can be partly attributed to general population trends but, additionally, to iatrogenic weight gain caused by insulin treatment. This association might be the missing link explaining the excess CVD burden observed in patients with T1DM despite optimal glycemic control. Data on newer agents for type 2 diabetes mellitus (T2DM) treatment are unraveling novel ways to challenge this aggravating coexistence.

Metformin: Is it a drug for all reasons and diseases?

Metformin was first used to treat type 2 diabetes in the late 1950s and in 2022 remains the first-choice drug used daily by approximately 150 million people. An accumulation of positive pre-clinical and clinical data has stimulated interest in re-purposing metformin to treat a variety of diseases including COVID-19. In polycystic ovary syndrome metformin improves insulin sensitivity. In type 1 diabetes metformin may help reduce the insulin dose. Meta-analysis and data from pre-clinical and clinical studies link metformin to a reduction in the incidence of cancer. Clinical trials, including MILES (Metformin In Longevity Study), and TAME (Targeting Aging with Metformin), have been designed to determine if metformin can offset aging and extend lifespan. Pre-clinical and clinical data suggest that metformin, via suppression of pro-inflammatory pathways, protection of mitochondria and vascular function, and direct actions on neuronal stem cells, may protect against neurodegenerative diseases. Metformin has also been studied for its anti-bacterial, -viral, -malaria efficacy. Collectively, these data raise the question: Is metformin a drug for all diseases? It remains unclear as to whether all of these putative beneficial effects are secondary to its actions as an anti-hyperglycemic and insulin-sensitizing drug, or result from other cellular actions, including inhibition of mTOR (mammalian target for rapamycin), or direct anti-viral actions. Clarification is also sought as to whether data from ex vivo studies based on the use of high concentrations of metformin can be translated into clinical benefits, or whether they reflect a 'Paracelsus' effect. The environmental impact of metformin, a drug with no known metabolites, is another emerging issue that has been linked to endocrine disruption in fish, and extensive use in T2D has also raised concerns over effects on human reproduction. The objectives for this review are to: 1) evaluate the putative mechanism(s) of action of metformin; 2) analyze the controversial evidence for metformin's effectiveness in the treatment of diseases other than type 2 diabetes; 3) assess the reproducibility of the data, and finally 4) reach an informed conclusion as to whether metformin is a drug for all diseases and reasons. We conclude that the primary clinical benefits of metformin result from its insulin-sensitizing and antihyperglycaemic effects that secondarily contribute to a reduced risk of a number of diseases and thereby enhancing healthspan. However, benefits like improving vascular endothelial function that are independent of effects on glucose homeostasis add to metformin's therapeutic actions.

Benefits of metformin add-on insulin therapy (MAIT) for HbA1c and lipid profile in adolescents with type 1 diabetes mellitus: preliminary report from a double-blinded, placebo-controlled, randomized clinical trial

OBJECTIVES

Metabolic control during puberty is impaired in Type 1 Diabetes Mellitus (T1DM) patients due to increased insulin resistance. Metformin is one of the oral medications typically used in type 2 diabetes mellitus to reduce insulin resistance. We aimed to examine the effect of metformin on glycemic indices and insulin daily dosage in adolescents with T1DM.

METHODS

The present clinical trial was carried out on 50 adolescents aged 10-20 years with T1DM referred to the Endocrinology Clinic of Mofid Children's Hospital in Tehran for nine months. The patients were randomly divided into two groups. In the first group, metformin was added to insulin therapy, while the second group continued routine insulin therapy combined with placebo. Hemoglobin A1c (HbA1c), weight, BMI, insulin dosage, and blood pressure were measured at the beginning of the study and repeated every three months. Serum lipid profile, creatinine, blood urea nitrogen, and liver enzymes were also measured twice: At the beginning and end of the study (after nine months).

RESULTS

The HbA1c level (p<0.001) and insulin dosage (p=0.04) were lower in the metformin group than in the placebo group after nine months. Daily insulin dosage variability was significantly lower in the metformin recipient group (p=0.041). Serum triglyceride, cholesterol, and creatinine were significantly lower in the metformin arm than in the placebo arm (p<0.05). However, metformin did not affect LDL, HDL, liver enzymes, and BUN.

CONCLUSIONS

Adjunctive metformin therapy reduces insulin dosage by inhibiting insulin resistance and weight gain. It helps decrease daily insulin dosage variability, which may prevent hypoglycemia. Also, metformin reduces creatinine, preventing renal failure in the long term.

Effect of metformin as an add-on therapy on neuregulin-4 levels and vascular-related complications in adolescents with type 1 diabetes: A randomized controlled trial

BACKGROUND

Inflammation is closely associated with atherosclerosis and plays a crucial role in the development of cardiovascular disease. Metformin sensitizes body cells to insulin, which may cause a reduction of atherogenic lipid fractions. Low neuregulin-4 (Nrg-4) levels, an adipokine, are linked to obesity, insulin resistance, impaired glucose tolerance and type 2 diabetes.

OBJECTIVES

We assessed the effect of oral supplementation with metformin on glycemic control, neuregulin-4 levels and carotid intima media thickness (CIMT) as a marker for subclinical atherosclerosis in adolescents with type 1 diabetes mellitus (T1DM) and microvascular complications.

METHODS

This randomized placebo-controlled trial included 80 type 1 diabetic patients with microvascular complications who were randomly divided to receive either 24 weeks of metformin 500 mg/day or matching placebo. Fasting blood glucose (FBG), HbA1c, C-reactive protein (CRP), urinary albumin creatinine ratio (UACR), lipid profile, Nrg-4 and CIMT were assessed at baseline and study end.

RESULTS

Both groups were well-matched as regards baseline clinical and laboratory data (p greater than 0.05). After 24-weeks, metformin therapy for the intervention group resulted in a significant decrease of HbA1c, CRP, UACR, total cholesterol and CIMT while Nrg-4 levels were increased compared with baseline levels (p < 0.001) and with placebo group(p < 0.001). Baseline Nrg-4 levels were negatively correlated to FBG, HbA1c, total cholesterol, CRP and CIMT. Metformin was well-tolerated.

CONCLUSIONS

Oral metformin supplementation once daily for 24 weeks as an adjuvant therapy to intensive insulin in pediatric T1DM was safe and effective in improving glycemic control, dyslipidemia and Nrg-4 levels; hence, it decreased inflammation, microvascular complications and subclinical atherosclerosis.

Changes of insulin resistance status and development of complications in type 1 diabetes mellitus: Analysis of DCCT/EDIC study

AIM

There is no longitudinal study regarding the changes of insulin resistance (IR) status and the development of complications in type 1 diabetes (T1D). By analyzing data sets from DCCT/EDIC study, we investigated the associations of IR status changes and diabetic complications in T1D.

MATERIALS AND METHODS

Estimated glucose disposal rate (eGDR) was calculated at entry of DCCT and in EDIC year 12 (average 18.5 years later) to represent IR. The participants (n = 957) were divided into four groups based on IR changes from baseline: RR group (stayed resistant; n = 49), RS group (became sensitive; n = 42), SR group (became resistant; n = 197), and SS group (stayed sensitive; n = 669). The association of diabetic complications were analyzed by using multivariable logistic regression models.

RESULTS

The improved IR decreased the risk of peripheral neuropathy, whereas the deteriorated IR increased the risk of diabetic complications including hypertension, peripheral artery disease, coronary artery calcification, retinopathy, albuminuria, peripheral neuropathy, and cardiac autonomic neuropathy (P < 0.05). Moreover, RR group (HR = 3.59, 95% CI (2.05-6.32)), RS group (HR = 2.27, 95% CI (1.11-4.64)) and SR group (HR = 1.90, 95% CI (1.24-2.92)) had higher risk of cardiovascular events compared to SS group (P < 0.05).

CONCLUSIONS

This study highlights the importance of IR changes represented by eGDR in the development of diabetic complications. Patients with T1D and IR may require intensive therapy.

New Developments in T Cell Immunometabolism and Therapeutic Implications for Type 1 Diabetes

Type 1 diabetes (T1D) is an autoimmune disease mediated by T cells and is becoming a serious public health threat. Despite the increasing incidence rate of T1D worldwide, our understanding of why T1D develops and how T cells lose their self-tolerance in this process remain limited. Recent advances in immunometabolism have shown that cellular metabolism plays a fundamental role in shaping T cell responses. T cell activation and proliferation are supported by metabolic reprogramming to meet the increased energy and biomass demand, and deregulation in immune metabolism can lead to autoimmune disorders. Specific metabolic pathways and factors have been investigated to rectify known deficiencies in several autoimmune diseases, including T1D. Most therapeutic strategies have concentrated on aerobic glycolysis to limit T cell responses, whereas glycolysis is the main metabolic pathway for T cell activation and proliferation. The use of metabolic inhibitors, especially glycolysis inhibitors may largely leave T cell function intact but primarily target those autoreactive T cells with hyperactivated metabolism. In this review, we provide an overview of metabolic reprogramming used by T cells, summarize the recent findings of key metabolic pathways and regulators modulating T cell homeostasis, differentiation, and function in the context of T1D, and discuss the opportunities for metabolic intervention to be employed to suppress autoreactive T cells and limit the progression of β-cell destruction.

Adjunctive Therapies to Optimize Closed-loop Glucose Control

Closed-loop insulin delivery systems are fast becoming the standard of care in the management of type 1 diabetes and have led to significant improvements in diabetes management. Nevertheless, there is still room for improvement for the closed-loop systems to optimize treatment and meet target glycemic control. Adjunct treatments have been introduced as an alternative method to insulin-only treatment methods to overcome diabetes treatment challenges and improve clinical and patient reported outcomes during closed-loop treatment. The adjunct treatment agents mostly consist of medications that are already approved for type 2 diabetes treatment and aim to complete the missing physiologic factors, such as the entero-endocrine system, that regulate glycemia in addition to insulin. This paper will review many of these adjunct therapies, including the basic mechanisms of action, potential benefits, side effects, and the evidence supporting their use during closed-loop treatment.

Cardiovascular Risk Management in Type 1 Diabetes

PURPOSE OF REVIEW

Type 1 diabetes mellitus (T1DM) is associated with increased mortality, with premature cardiovascular disease (CVD) a major factor. To date, research has identified multiple risk factors for this excess CVD liability. However, gaps remain in our understanding of the underlying mechanisms.

RECENT FINDINGS

T1DM is generally diagnosed at a young age. Since cardiovascular complications often only manifest at a later stage of life, there is generally less focus in earlier years on reducing CVD risk for affected individuals. This is an area that requires improvement as risk factors might be managed from earlier age to reduce later development of CVD. In this review, we discuss the evidence for cardiovascular risk factors, risk prediction models, candidate surrogate measurements and CVD risk management.

Current and future therapies for type 1 diabetes

In type 1 diabetes, insulin remains the mature therapeutic cornerstone; yet, the increasing number of individuals developing type 1 diabetes (predominantly children and adolescents) still face severe complications. Fortunately, our understanding of type 1 diabetes is continuously being refined, allowing for refocused development of novel prevention and management strategies. Hitherto, attempts based on immune suppression and modulation have been only partly successful in preventing the key pathophysiological feature in type 1 diabetes: the immune-mediated derangement or destruction of beta cells in the pancreatic islets of Langerhans, leading to low or absent insulin secretion and chronic hyperglycaemia. Evidence now warrants a focus on the beta cell itself and how to avoid its dysfunction, which is putatively caused by cytokine-driven inflammation and other stress factors, leading to low insulin-secretory capacity, autoantigen presentation and immune-mediated destruction. Correspondingly, beta cell rescue strategies are being pursued, which include antigen vaccination using, for example, oral insulin or peptides, as well as agents with suggested benefits on beta cell stress, such as verapamil and glucagon-like peptide-1 receptor agonists. Whilst autoimmune-focused prevention approaches are central in type 1 diabetes and will be a requirement in the advent of stem cell-based replacement therapies, managing the primarily cardiometabolic complications of established type 1 diabetes is equally essential. In this review, we outline selected recent and suggested future attempts to address the evolving profile of the person with type 1 diabetes.

Hundert Jahre – Insulin bleibt aktuell und notwendig

In der Behandlung des Typ-1-Diabetes ist die Therapie mit Insulin auch 100 Jahre nach seiner Entdeckung weiterhin eine lebensnotwendige Therapie. Der pharmakologische Fortschritt hat die Behandlung erheblich erleichtert und nähert sich der physiologischen Insulin-Sekretion zunehmend an. In der Behandlung des Typ-2-Diabetes hingegen ist die Insulin-Therapie bei den meisten Patienten zunächst nicht notwendig. Lebensstil-Interventionen und moderne Nicht-Insulin Antidiabetika können häufig zu einer lang andauernden Kontrolle der Erkrankung führen. Die Heterogenität des Typ-2-Diabetes führt jedoch dazu, dass einige Patienten früh von einer Insulin-Therapie profitieren. Auch beim Typ-2-Diabetes können moderne Insulin Präparate die Insulin-Behandlung deutlich erleichtern, auch in Kombination mit anderen Antidiabetika. Einleitung und Begleitung einer Insulin-Therapie gehören somit weiterhin zu den Kernaufgaben der Diabetologie.

The Protective Effects of L-Carnitine and Zinc Oxide Nanoparticles Against Diabetic Injury on Sex Steroid Hormones Levels, Oxidative Stress, and Ovarian Histopathological Changes in Rat

Diabetes mellitus is a common chronic metabolic disorder. This study aimed to investigate the effects of co-treatment with L-carnitine (LC) and zinc oxide nanoparticles (ZnONPs) on serum levels of sex hormones, oxidative stress, and ovarian histopathology in streptozotocin (STZ)-induced diabetic rats. Female Wistar rats (n = 56, 180-220 g) received a single intraperitoneal (IP) injection of STZ (65 mg/kg). They were randomly assigned into the following groups: diabetic group (Dia), Dia+Met group (100 mg metformin/kg/day), Dia+LC group (200 mg/kg/day), Dia+ZnONPs group (10 mg/kg/day), and Dia+LC+ZnONPs group (200 mg LC/kg/day and 10 mg ZnONPs/kg/day). Control group (Ctl) received the same volume of STZ solvent. After 21 days of treatment, blood serum was centrifuged for sex hormone assays. The right ovary was used for biochemical analysis, and the left ovary was fixed in 10% neutral buffered formalin for histological assessment. The levels of estradiol, progesterone, FSH, and LH significantly increased in the Dia+ZnONPs+LC group (P < 0.001) compared with the Dia group. Co-treatment with LC and ZnONPs reduced malondialdehyde and carbonyl protein and increased glutathione, catalase, and superoxide dismutase activities in ovarian tissue compared with the Dia group (P < 0.05). Moreover, the number of all ovarian follicles significantly increased in this group compared with the Dia group (P < 0.05). The results of this study indicated that co-treatment with LC and ZnONPs could preserve ovarian function by increasing sex hormones levels and antioxidant activity and decreasing lipid peroxidation in diabetic rats. Therefore, this compound supplementation may improve ovulation and fertility in people with diabetes mellitus.

Cucurbitacin B Suppresses Hyperglycemia Associated with a High Sugar Diet and Promotes Sleep in Drosophila melanogaster

Secondary metabolites enable plants to protect themselves from herbivorous insects. Among these, cucurbitacin B (cuc-B) is a bitter-tasting compound with promising pharmacological potential. Dietary exposure to cuc-B lowered the hemolymph glucose levels of Drosophila melanogaster fed with a high carbohydrate diet, which is homologous to high blood glucose in humans, and its effect was comparable to that of metformin, a well-known glucose-lowering drug. Furthermore, cuc-B reduced tissue sugar levels and glycogen levels, as well as triacylglycerol levels. Our results thus highlight the potential applicability of this compound to treat chronic metabolic diseases such as diabetes and obesity. Additionally, we analyzed sleep quality and taste-associative memory enhancement after cuc-B and metformin treatment. Both supplements increased nighttime bout length and metformin increased memory consolidation. Therefore, discarded shell of Cucurbitaceae could be processed into health supplements.

Double Diabetes: A Growing Problem Requiring Solutions

The growing proportion of type 1 diabetes mellitus (T1DM) patients with clinical features of insulin resistance (IR) has led to the description of a distinctive T1DM subgroup, still unrecognised by current guidelines, called double diabetes, assumingly associated with poorer metabolic phenotype and increased risk of micro- and macrovascular complications. The main goal of identifying double diabetes, estimated to be present in up to half of T1DM patients, is timely implementation of appropriate therapeutic interventions to reduce the increased risk of chronic complications and other adverse metabolic traits associated with this condition. Proposed diagnostic criteria are largely divided into three different groups: family history of type 2 diabetes mellitus (T2DM), obesity/metabolic syndrome, and IR. Estimated glucose disposal rate may prove the most reliable marker of double diabetes. In addition to general measures (diet, physical activity, antihypertensive, and lipid-lowering medications, etc.) and development of new insulin preparations with more hepatic action, double diabetes patients may derive more benefit from agents developed for T2DM. Indeed, such potentially promising agents include glucagon-like peptide-1 receptor agonists, sodium-glucose contrasporter-2 inhibitors, and their combination. We are now awaiting long-term trials assessing metabolic and vascular benefits of these medications in double diabetes.

The Current and Potential Therapeutic Use of Metformin-The Good Old Drug

Metformin, one of the oldest oral antidiabetic agents and still recommended by almost all current guidelines as the first-line treatment for type 2 diabetes mellitus (T2DM), has become the medication with steadily increasing potential therapeutic indications. A broad spectrum of experimental and clinical studies showed that metformin has a pleiotropic activity and favorable effect in different pathological conditions, including prediabetes, type 1 diabetes mellitus (T1DM) and gestational diabetes mellitus (GDM). Moreover, there are numerous studies, meta-analyses and population studies indicating that metformin is safe and well tolerated and may be associated with cardioprotective and nephroprotective effect. Recently, it has also been reported in some studies, but not all, that metformin, besides improvement of glucose homeostasis, may possibly reduce the risk of cancer development, inhibit the incidence of neurodegenerative disease and prolong the lifespan. This paper presents some arguments supporting the initiation of metformin in patients with newly diagnosed T2DM, especially those without cardiovascular risk factors or without established cardiovascular disease or advanced kidney insufficiency at the time of new guidelines favoring new drugs with pleotropic effects complimentary to glucose control. Moreover, it focuses on the potential beneficial effects of metformin in patients with T2DM and coexisting chronic diseases.

Adjunctive therapies in type 1 diabetes mellitus

PURPOSE OF REVIEW

Insulin is the mainstay of treatment in people living with type 1 diabetes mellitus due to an immune-mediated loss of beta cells. Yet despite advances in insulin therapy and other technological advances, glycemic control remains difficult to achieve. Therefore, we aim to highlight risks and benefits of adjunctive therapies that may improve type 1 diabetes care.

RECENT FINDINGS

We identified studies assessing clinical outcomes of adjunctive therapies that are both Food and Drug Administration (FDA)-approved and off-label in type 1 diabetes. Adjunctive therapies reviewed included metformin, pramlintide, glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose cotransporter-2 inhibitors.

SUMMARY

Although insulin is required in people living with type 1 diabetes mellitus, adjunctive therapies may positively impact glycemic control, reduce insulin requirements and lead to weight loss. In addition, the risk of hypoglycemia, gastrointestinal side effects and diabetes ketoacidosis may be increased with the use of these adjunctive therapies. Pramlintide is currently the only FDA-approved adjunctive therapy, whereas others require continued research to better understand risk-to-benefit ratio.

Association of British Clinical Diabetologists (ABCD) and Diabetes UK joint position statement and recommendations on the use of sodium-glucose cotransporter inhibitors with insulin for treatment of type 1 diabetes (Updated October 2020)

Dapagliflozin (SGLT-2 inhibitor) and sotagliflozin (SGLT1/2 inhibitor) are two of the drugs of SGLT inhibitor class which have been recommended by the National Institute for Health and Care Excellence (NICE) in people with type 1 diabetes with BMI ≥27 kg/m² . Dapagliflozin is licensed in the UK for use in the NHS while sotagliflozin may be available in future. These and possibly other SGLT inhibitors may be increasingly used in people with type 1 diabetes as new licences are obtained. These drugs have the potential to improve glycaemic control in people with type 1 diabetes with the added benefit of weight loss, better control of blood pressure and more time in optimal glucose range. However, SGLT inhibitors are associated with a higher incidence of diabetic ketoacidosis without significant hyperglycaemia. The present ABCD/Diabetes UK joint updated position statement is to guide people with type 1 diabetes and clinicians using these drugs help mitigate this risk and other potential complications. Particularly, caution needs to be exercised in people who are at risk of diabetic ketoacidosis due to low calorie diets, illnesses, injuries, starvation, excessive exercise, excessive alcohol consumption and reduced insulin administration among other precipitating factors for diabetic ketoacidosis.

Nutrition and Obesity in the Pathogenesis of Youth-Onset Type 1 Diabetes and Its Complications

Since the 1980s, there has been a dramatic rise in the prevalence of overweight and obesity in pediatric populations, in large part driven by sedentary lifestyles and changing dietary patterns with more processed foods. In parallel with the rise in pediatric obesity in the general population, the prevalence of overweight and obesity has increased among children and adolescents with type 1 diabetes. Adiposity has been implicated in a variety of mechanisms both potentiating the risk for type 1 diabetes as well as exacerbating long-term complications, particularly cardiovascular disease. Treatment options targeting the unique needs of obese pediatric patients, both before and after diagnosis of type 1 diabetes, are limited. In this review, we discuss the history of the epidemiology of the obesity epidemic in the context of pediatric type 1 diabetes, highlight the possible role of obesity in type 1 diabetes pathogenesis and review the concept of "double diabetes". The impact of obesity at and after diagnosis will be discussed, including noted differences in clinical and biochemical markers, lipid abnormalities, and long-term cardiovascular complications. Finally, we will review the existing literature on pharmacologic and nutritional interventions as potential treatment strategies for youth with coexisting type 1 diabetes and obesity.

Predisposing factors for the development of diabetic ketoacidosis with lower than anticipated glucose levels in type 2 diabetes patients on SGLT2-inhibitors: a review

PURPOSE

SGLT2-inhibitors (SGLT-2i) have been linked to the risk of potential life-threatening diabetic ketoacidosis (DKA). The U.S. Food and Drug Administration and the European Medicines Agency issued warnings in 2015 and 2016 respectively on the predisposing factors to the development of DKA in individuals on an SGLT2i. New predisposing factors to DKA are still being discovered with the use of SGLT-2i. The list by FDA and EMA is yet to be updated. This article aims to provide a holistic list that includes the newer factors that have been implicated in the development of DKA. The overall aim is to guide physicians in prescribing this class of drugs for type 2 diabetes mellitus (T2D).

METHOD

A search was done using PUBMED, Google Scholar, and Directory of Open Access Journals with the following words: SGLT-2 Inhibitors AND Ketoacidosis were entered. We included articles from 2000 to 2020, those in English, those involving any of the approved SGLT2i medications in T2D patients, and studies that focused on DKA linked to SGLT-2i. These articles were reviewed, and relevant data extracted and compiled.

RESULTS AND CONCLUSION

The review has revealed that predisposing factors include (excess) alcohol consumption, female gender, starvation due to illness or fasting, withholding the use of SGLT2i for less than 48 h peri-operatively, and the existence of a variations in the expression of SGLT2 receptors. Patients should be advised on "sick day rules," and if a patient becomes unwell while on an SGLT2i, they should be advised to withhold the medication for the duration of the intercurrent illness.

The Causes of Insulin Resistance in Type 1 Diabetes Mellitus: Is There a Place for Quaternary Prevention?

Diabetes mellitus was the first non-communicable disease that was recognized by the United Nations as a 21st-century pandemic problem. Recent scientific reports suggest that people with type 1 diabetes mellitus also develop insulin resistance, which is generally considered to be a distinctive feature of type 2 diabetes mellitus. The causes of insulin resistance in type 1 diabetes mellitus were explored, but there was a lack of publications that connected the risk factors of insulin resistance in type 1 diabetes mellitus with the proposition of repair mechanisms that are offered by quaternary prevention. Toward this end, the present review is an attempt to combine the previous reports on the causes of insulin resistance in type 1 diabetes mellitus and a brief review of quaternary prevention. The destructive effect of insulin resistance on many physiological processes that predisposes the individual to chronic diabetes complications creates an urgent need to introduce effective therapeutic methods for preventing the development and progression of this pathology.

Metformin: Up to Date

BACKGROUND

Metformin is an oral hypoglycemic agent extensively used as first-line therapy for type 2 diabetes. It improves hyperglycemia by suppressing hepatic glucose production and increasing glucose uptake in muscles. Metformin improves insulin sensitivity and shows a beneficial effect on weight control. Besides its metabolic positive effects, Metformin has direct effects on inflammation and can have immunomodulatory and antineoplastic properties.

AIM

The aim of this narrative review was to summarize the up-to-date evidence from the current literature about the metabolic and non-metabolic effects of Metformin.

METHODS

We reviewed the current literature dealing with different effects and properties of Metformin and current recommendations about the use of this drug. We identified keywords and MeSH terms in Pubmed and the terms Metformin and type 2 diabetes, type 1 diabetes, pregnancy, heart failure, PCOS, etc, were searched, selecting only significant original articles and review in English, in particular of the last five years.

CONCLUSION

Even if many new effective hypoglycemic agents have been launched in the market in the last few years, Metformin would always keep a place in the treatment of type 2 diabetes and its comorbidities because of its multiple positive effects and low cost.

Current status of metformin in addition to insulin therapy in adult patients with type 1 diabetes mellitus: An analysis from the Guangdong Type 1 Diabetes Mellitus Translational Medicine Study

BACKGROUND

Limited data on the efficacy of the additional metformin therapy in patients with type 1 diabetes mellitus (T1DM) under real-life conditions have been available so far.

METHODS

Patients aged ≥18 years with a duration of T1DM for at least 1 year were included in this multicenter observational study. Patients with insulin combined with metformin therapy (MET group) were compared with those with insulin therapy only (INS group).

RESULTS

A total of 76 patients in the MET group were compared with 655 patients in the INS group. At baseline, patients with dyslipidemia were more prevalent in the MET group (17.6% vs 9.0%; P = .006), and they also had a higher body mass index (BMI) (21.7 ± 3.2 kg/m² vs 20.4 ± 2.6 kg/m² ; P < .001) than those in the INS group. But glycosylated hemoglobin (HbA1c) and daily insulin dose were not significantly different between the two groups. After 1-year follow-up, HbA1c decreased in both groups, while the daily insulin dose decreased in the MET group, but did not change in the INS group (-0.02 IU/kg [-0.16, 0.09] vs 0 IU/kg [-0.09, 0.09]; P = .029). The additional metformin therapy led to no change of BMI and weight in the MET group, while the body weight increased from 53.7 ± 8.6 kg to 55.0 ± 7.9 kg in the INS group (P < .001).

CONCLUSIONS

Metformin is initiated more in T1DM patients with dyslipidemia or higher BMI in current practice in China. The addition of metformin is effective in maintaining weight and reducing the insulin dosage without improving glycemic control in patients with T1DM.

Adjunct therapies in treatment of type 1 diabetes

In spite of developments with novel insulin preparations, novel modes of insulin delivery with insulin infusion pumps, and the facility of continuous glucose monitoring, only 20% of patients with type 1 diabetes are under adequate control. The need for innovation is clear, and, therefore, the use of adjunct therapies with other pharmacological agents currently in use for type 2 diabetes, has been tried. Currently, pramlintide is the only agent licensed for use in this condition in addition to insulin. Global trials have been conducted with liraglutide, a glucagon-like peptide 1 receptor agonist (GLP-1RA), dapagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, and sotagliflozin, an inhibitor of both SGLT1 and SGLT2 transporters. While dapagliflozin and sotagliflozin have now been licensed for clinical use in this condition in Europe and Japan, they have hitherto not been licensed in the United States due to a small increase in the risk of diabetic ketoacidosis. However, these agents reduce glycosylated hemoglobin (HbA1c) by 0.4%, reduce glycemic oscillations, and do not increase the risk of hypoglycemia. Liraglutide, on the other hand, induced a smaller reduction in HbA1c and thus was not considered for a license. However, further trials are currently being conducted with a combination of semaglutide, the most potent GLP-1RA, and dapagliflozin to determine whether this approach would yield better outcomes.

The clinical application of metformin in children and adolescents: A short update

Metformin is a widely used drug that results in clear benefits in relation to glucose metabolism and diabetes-related complications. The global increase in the prevalence of obesity among children and adolescents is accompanied by the appearance and increasing prevalence of insulin resistance, prediabetes, and type 2 diabetes mellitus (T2DM). In addition, children, and adolescents with premature pubarche and polycystic ovary have considerable degree of insulin resistance. The insulin sensitizing actions of metformin encouraged many investigators and physician to use it as the key drug in these conditions for both prevention and treatment. However, long term-controlled studies are still required to assess the degree and duration of effectiveness and safety of using metformin. This review tries to update physicians about the main and the new therapeutic perspectives of this drug.

The Effect of Nigella Sativa on Renal Oxidative Injury in Diabetic Rats

Oxidative stress plays a key role in the evolution of diabetes complications. The current study looked into the potential effects of the hydroalcoholic extract of Nigella sativa on the oxidative injury of the rat kidneys in diabetic animals. The animals were placed into five study groups in a random manner as follows: (1) control, (2) diabetic, (3 and 4) treatment with two doses of N. sativa extract (200 and 400 mg/kg), and (5) treatment with metformin (300 mg/kg). The time course of administration was six weeks. The malondialdehyde (MD A) and total thiol groups, as well as the superoxide dismutase and catalase activities, were also assessed in the renal tissue and lipid profile in serum. In the diabetic groups, the level of MDA significantly increased (P < 0.01) and antioxidant levels decreased compared to the control (P < 0.05). In treated rats with N. sativa, the antioxidant status of renal tissue was improved (P < 0.05 to P < 0.001). The lipid profile also improved in the rats treated with the extract (P < 0.001). Our findings suggest that long-term administration of N. sativa in diabetic rats induced by streptozotocin can improve the status of the oxidative stress in kidney tissue.

Pharmacological therapies to address obesity in type 1 diabetes

PURPOSE OF REVIEW

Obesity is increasing in prevalence among patients with type 1 diabetes (T1D) and is associated with insulin resistance and increased cardiovascular risk. The management of obesity in this population is complicated by defects in pancreatic islet hormone secretion and the effects of exogenous insulin treatment. Here, we review the effects of antiobesity medications and adjunct-to-insulin medications on body weight in T1D.

RECENT FINDINGS

There is a profound evidence gap around the use of drugs for the treatment of obesity in T1D since systematic studies have not been performed in this population. Adjunctive-to-insulin therapy with certain antihyperglycemic agents leads to modest weight loss and reductions in insulin dose in T1D. However, only pramlintide has been approved in the United States for clinical use as adjunctive therapy in T1D.

SUMMARY

The growing prevalence of obesity in T1D has created an unmet need for safe and effective therapies to treat overweight and obesity in this population. Currently, antiobesity medications are used off-label for the treatment of patients with T1D. Additional studies are needed to understand the role of these medications in the management of obesity in patients with T1D.

Reducing Type 1 Diabetes Mortality: Role for Adjunctive Therapies?

Individuals with type 1 diabetes (T1D) frequently fail to achieve glycemic goals and have excess cardiovascular risk and premature death. Adjunctive agents may play a role in reducing morbidity, mortality, and the adverse sequelae of insulin treatment. A surge in type 2 diabetes drug development has revealed agents with benefits beyond glucose lowering, including cardiovascular risk reduction. Could these benefits translate to T1D? Specific trials for T1D demonstrate substantial hemoglobin (Hb)A1c reductions with sodium glucose cotransporter inhibitors (SGLTis) and glucagon-like peptide (GLP)1 agonists, and modest improvements with metformin, dipeptidyl peptidase-4 inhibitor (DPP4i), and pramlintide. Studies exploring cardiovascular risk reduction are warranted. This review synthesizes the emerging literature for researchers and clinicians treating people with T1D. Challenges in T1D research are discussed.

New Frontiers in the Treatment of Type 1 Diabetes

Type 1 diabetes is an autoimmune disease caused by the immune-mediated destruction of pancreatic β cells that results in lifelong absolute insulin deficiency. For nearly a century, insulin replacement has been the only therapy for most people living with this disease. Recent advances in technology and our understanding of β cell development, glucose metabolism, and the underlying immune pathogenesis of the disease have led to innovative therapeutic and preventative approaches. A paradigm shift in immunotherapy development toward the targeting of islet-specific immune pathways involved in tolerance has driven the development of therapies that may allow for the prevention or reversal of this disease while avoiding toxicities associated with historical approaches that were broadly immunosuppressive. In this review, we discuss successes, failures, and emerging pharmacological therapies for type 1 diabetes that are changing how we approach this disease, from improving glycemic control to developing the "holy grail" of disease prevention.

Effect of metformin on clinical and biochemical hyperandrogenism in adolescent girls with type 1 diabetes

Background Hyperandrogenism with or without polycystic ovarian syndrome is seen in adolescents with type 1 diabetes (T1D), especially those with suboptimal control. Objective To assess the effect of metformin on hyperandrogenism and ovarian function in adolescents with T1D. Methods This prospective study included 28 T1D females showing signs of hyperandrogenism. History taking (detailed diabetes history and menstrual history) and anthropometric measurements (weight, height, body mass index [BMI], waist and hip circumference) were initially performed, and then the patients were assessed for the manifestations of hyperandrogenism (acne, hirsutism as well as pelvic ultrasound [U/S] for ovarian morphology). Biochemical evaluation for ovulation (progesterone assessment during the luteal phase), sex steroids (estradiol, testosterone, dehydroepiandrosterone sulfate [DHEAS] and androstenedione), prolactin, glycemic control (hemoglobin A1c [HbA1c]) and gonadotropin levels (follicle stimulating hormone [FSH] and luteinizing hormone [LH]) was done. Patients were subjected to 500 mg metformin twice daily orally for 1 year, and then the patients were re-evaluated for clinical and biochemical parameters. Results Metformin therapy resulted in a significant reduction in weight (p = 0.001), BMI (p = 0.002), acne (p = 0.008), hirsutism score (0.007), LH (p = 0.008), testosterone (p < 0.001) and androstenedione levels (p = 0.028) in adolescent girls with T1D. Regarding menstrual irregularities, there was a significant reduction in the number of patients with oligomenorrhea (68%) with a p value of <0.001. However, there were no significant reduction in the daily insulin requirements (p = 0.782) or HbA1c (p = 0.068). Nausea and/or abdominal pain were the commonly reported side effects of metformin (64%). Conclusions Metformin as an insulin sensitizing agent improved the BMI and cycle regularity together with clinical and biochemical hyperandrogenism in T1D adolescent girls. However, it did not improve their glycemic control.

Pharmacologic treatment options for type 1 diabetes: what's new?

INTRODUCTION

The expanding variety of insulins, including biosynthetic human insulin and rapid and long-acting insulin analogs, have dramatically transformed the management of type 1 diabetes (T1D) over the past 25 years. Moreover, increasing interest in the use of novel drugs developed for the treatment of type 2 diabetes (T2D) as adjunctive therapies for T1D remains a work in progress. Areas Covered: We reviewed articles published up to December 2018 in PubMed and ClinicalTrials.gov for recent developments in the pharmacologic treatment of T1D, including inhaled insulin, ultrafast and ultralong-acting insulins and adjunctive therapies including pramlintide, metformin, GLP-1 receptor agonists, DPP-4 inhibitors, SGLT-2, and SGLT1/2 inhibitors. Expert Opinion: With the creation of ultrafast-acting insulin analogs and very prolonged duration of action of basal insulins, it is possible to more closely mimic physiologic insulin secretion. Adjunctive therapies, likewise, may also overcome some of the abnormal physiology that is a hallmark of T1D. Therefore, individualized consideration of the efficacy of these agents must be measured alongside the potential adverse effects when choosing an adjunctive therapy.

Prescribing of diabetes medications to people with type 2 diabetes and chronic kidney disease: a national cross-sectional study

BACKGROUND

Previous studies in general practice and hospital settings have identified that prescribing of non-insulin diabetes medications may be sub-optimal in people with type 2 diabetes (T2D) and renal impairment. Since these publications, a number of new medications have become available for the management of T2D. Study aims were to, in a cohort of Australians with T2D and renal impairment attending general practice, (1) investigate whether the prescribing of non-insulin diabetes medications is consistent with dosing adjustments recommended within current Australian Diabetes Society (ADS) guidelines; and (2) identify patient socio-demographic and clinical factors associated with at least one prescription of a non-insulin diabetes medication inconsistent with current ADS guidelines for medication doses.

METHODS

Cross-sectional study using data from the MedicineInsight general practice database managed by NPS MedicineWise. Patients with T2D who were aged 18 years and over, with an average eGFR< 60 ml/min/1.73m2 and at least one prescription of a non-insulin diabetes medication between 1st January 2015 and 30th June 2017 were included. Descriptive statistics were used to summarise patient characteristics and medication use. Marginal logistic regression models were used to estimate associations between sociodemographic and clinical factors and prescribing of ≥1non-insulin diabetes medicine not consistent with ADS guidelines.

RESULTS

The majority of the 3505 patients included (90.4%) had an average eGFR of 30-59 ml/min/1.73m2. In terms of absolute numbers, metformin was the medication most frequently prescribed at a dose not consistent with current ADS guidelines for dosing in renal impairment (n = 1601 patients), followed by DPP4 inhibitors (n = 611) and sulphonylureas (n = 278). The drug classes with the highest proportion of prescriptions with dosage not consistent with ADS guidelines were SGLT2 inhibitors (83%), followed by biguanides (58%) and DPP4 inhibitors (46%). Higher HbA1c, longer known diabetes duration and diagnosis of retinopathy were associated with receiving ≥1prescription with a dosage not consistent with guidelines.

CONCLUSIONS

Prescribing of non-insulin diabetes medications at doses inconsistent with current ADS guideline recommendations for dosing adjustments for people with renal impairment was common. Further research is needed to understand how general practitioners access, interpret and apply the ADS guidelines and the impact this may have on patient outcomes.

Early Occurrence Cases of Diabetes Mellitus: Clinical Picture in Two Major Tertiary Care Hospitals in India

INTRODUCTION

Type 1 diabetes mellitus (T1D) is one of the most common endocrine diseases in childhood. However, very limited information is available on this disease.

OBJECTIVES

This study was done to assess risk factors, clinical features and management practices in T1D patients.

METHODS

A review of records of 39 T1D cases admitted over the past five years in two hospitals was done.

RESULTS

The mean age at diagnosis among males (n=21) was 19.9±10.3 years and among females (n=18) was 12.3±7.5 years (t=2.614, p=0.013). Mean age at diagnosis of patients who were underweight (n=7) was 9.9±4.4 years, compared to 17.8±10.1 years among patients (n=32) with normal or overweight status (t=2.028, p=0.05). The family history of T1D was present among 7(18.0%) cases. The most common symptoms among the cases were fatigue 22(56.4%), polyuria 19(48.7%) and polydipsia 18(46.1%). The most common sign was weight loss 27(69.2%). The most common complications were diabetic nephropathy and skin infections seen each among 10(25.6%) cases. Mean duration of T1D was significantly more among patients with diabetic nephropathy (p<0.001), compared to those without. Mean HbA1c value among patients was 12.9±2.7. It was significantly more among patients with Diabetic Ketoacidosis (DKA) (p=0.012). A short-acting insulin was used in the management of T1D among 59.5% cases. The outcome of the management showed a loss of one patient who developed DKA.

CONCLUSION

Routine growth monitoring and blood glucose analysis is required among T1D cases. The present study provides a database of risk factors, clinical features, and management practices among patients with T1D in this region and addresses several issues important to both patients and their care providers.

Adjunct Antihyperglycemic Agents in Overweight and Obese Adults With Type 1 Diabetes

OBJECTIVE

People with type 1 diabetes often have suboptimal glycemic control. The gold standard of treatment is basal-bolus insulin or subcutaneous insulin infusion via insulin pump. Although insulin therapy improves glycemic control, weight gain and hypoglycemia often limit achievement of hemoglobin A_1C (A1C) goals. The number of people with type 1 diabetes who are overweight or obese is increasing, and there are many similarities between what was historically called type 1 and type 2 diabetes. Therefore, there is rationale for using antihyperglycemic agents that target other pathophysiological abnormalities to facilitate weight loss and improve glycemic control.

DATA SOURCES

We performed a MEDLINE search from 1975 through October 2018 to identify articles that studied noninsulin agents in adults with type 1 diabetes and body mass index (BMI) ≥25 kg/m².

STUDY SELECTION AND DATA EXTRACTION

Identified articles were included if the study duration was ≥4 weeks, included ≥20 patients, and set mean baseline BMI ⩾25kg/m².

DATA SYNTHESIS

This review summarizes 32 clinical trials. Amylin mimetics, sodium-glucose-like transporter-2 inhibitors, and glucagon-like-peptide-1 receptor agonists demonstrate the greatest improvements in body weight and A1C. The most common adverse effects are hypoglycemia and ketosis. Relevance to Patient Care and Clinical Practice: Patients with type 1 diabetes may have interest in starting noninsulin agents. Clinicians need to be knowledgeable in the efficacy and adverse effect profile of these agents, specifically in people with type 1 diabetes.

CONCLUSIONS

Adding noninsulin antihyperglycemic agents may benefit select overweight or obese adults with type 1 diabetes. These agents are off-label, and if used, close monitoring is essential.